Recently, large-capacity digital versatile discs (DVDs) capable of permanently storing high-quality video and audio in comparison with compact discs (CDs) have been developed, commercialized and supplied. Types of the DVDs include a DVD-read only memory (DVD-ROM), a write once DVD recordable (DVD-R), a DVD-random access memory (DVD-RAM) or DVD rewritable (DVD-RW), etc.
Standardization of a high-density rewritable optical disc, e.g., a Blu-ray disc rewritable (BD-RE), capable of recording high-density data, is ongoing. The BD-RE will be described in detail.
FIG. 1 shows recording unit blocks (RUBs) of a high-density rewritable optical disc, e.g., a Blu-ray disc rewritable (BD-RE). As shown in FIG. 1, a single RUB consisting of a run-in area, physical cluster area and run-out area or a sequence of RUBs consisting of run-in areas, physical cluster areas, run-out areas and the third guard area (Guard_3) located in a tail of the sequence of RUBs can be recorded in a BD-RE 100. In the sequence of the RUBs, each RUB consisting of the run-in area, the physical cluster area and the run-out area can be repeated twice or more.
As shown in FIG. 2, the run-in area includes the first guard area (Guard_1) and a preamble area (PrA). The preamble area includes the first synchronous data (Sync_1) and the second synchronous data (Sync_2). The first synchronous data and second synchronous data include 24-bit synchronous body data and a 6-bit synchronous ID, respectively.
The first and second synchronous data items are discriminated by different unique synchronous IDs. For example, the first synchronous data has a value of “000 100” as the synchronous ID. The second synchronous data has a value of “010 000” as the synchronous ID.
As shown in FIG. 3, the run-out area can include a post-amble area (PoA) and the second guard area (Guard_2). The post-amble area contains the third synchronous data (Sync_3). The third synchronous data includes 24-bit synchronous data and a 6-bit synchronous ID. The 6-bit synchronous ID of the third synchronous data is different from the 6-bit synchronous IDs of the first and second synchronous data. For example, the 6-bit synchronous ID of the third synchronous data has a value of “000 001”.
The video and audio data recorded in the physical cluster area are read in synchronization with the synchronous data recorded in the run-in and run-out areas. Then, the video and audio data are reproduced as original video and audio signals through a reproduction signal processor such as a moving picture experts group (MPEG) decoder.
As shown in FIG. 4, the physical cluster area can contain a data stream associated with video data of moving pictures and audio data, frame synchronous information, a long distance error correction (LDC) code, a burst indicator sub-code (BIS) and an address unit (AU).
The LDC code and BIS are recorded on the basis of well-known Reed-Solomon code words for error correction. The AU is used for correctly searching for a position of recorded data. As shown in FIG. 5, the physical cluster area contains 16 AUs (AU 0-AU 15). An AU of 9 bytes includes address unit (AU) number information, flag bits, etc. The flag bits are reserved and set to “00h”.
As shown in FIG. 6, the AU numbers are linked to physical sector numbers and also linked to physical address in pre-groove (ADIP) addresses. The AU number is useful as reference information in searching for the position of recorded data.
Thus, an optical disc apparatus such as a BD-RE recorder, etc. reads and confirms the physical sector numbers and physical ADIP addresses linked to the AU numbers. Then, the optical disc apparatus searches for a video and audio data stream recorded in the physical cluster area and then reads the searched data stream. Then, the optical disc apparatus performs an MPEG decoding operation to reproduce and output original video and audio signals.
Recently, it has been expected that the high-density optical disc, e.g. the BD-ROM, corresponding to the high-density rewritable optical disc will be developed. The high-density optical disc such as the BD-ROM must be able to maintain reproduction compatibility with a high-density rewritable optical disc such as a BD-RE on which data is recorded in a discontinuous recording format and must be able to prevent unauthorized or unlawful usage. However, there is not yet provided a method for effectively maintaining the above-described reproduction compatibility and preventing the unauthorized or unlawful usage.